J.’s article on the new Jewish population estimates published by the Steinhardt Social Research Institute at Brandeis University (“Study suggests precipitous drop in local Jewish population,” Oct. 4) opened with a tongue-in-cheek jab at the seeming disappearance of 240,000 Jews from the Bay Area.
It’s understandable why Bay Area residents would feel slighted and would wonder if these numbers are pulled out of thin air. The article, written by Dan Pine, accurately portrays the challenges of preparing estimates of the Jewish population. The simplest part of the equation is often the most complex. As Pine points out, how you define who is a Jew is the 240,000-person question.
The article misrepresents the numbers, however, making it difficult to discern fact from fiction. It is stated that our study “tallied the Bay Area’s entire Jewish adult population at just over 122,000.” This is based on a figure in the report not of the entire Jewish population, but of adults who identify as Jewish when asked about their religion. Estimates of the total population, which we provide at the national level, requires adding estimates of Jewish adults missed by the religion question (Jews not by religion) and Jewish children. At the national level, we estimate about 19 percent of Jewish adults are missed by the religion question. The recently released Pew survey estimated this at around 22 percent.
The rate within specific communities varies. In the East Bay federation’s 2011 survey, it was closer to 30 percent of Jewish adults. In the S.F.-based federation’s 2004 study, it was closer to our national estimate of 19 percent. Furthermore, the counties covered by the three studies do not align, making direct comparisons difficult.
With regard to the comments offered by Bruce Phillips, lead author of San Francisco’s 2004 study, the SSRI estimates, for purposes of population estimation, are not limited by having information only about the individuals interviewed rather than all members of the household. All of the surveys we included were designed to provide representative samples of adults in the U.S. Thus, the randomly selected respondents, when weighted appropriately, are representative of all adults in the population. This obviates the need to ask the religious identity of each household member.
Most important, we tried to make clear on the website and in the report that the county-level estimates are preliminary and should be read (and cited) with appropriate caution. Some counties are better represented in our large sample of national surveys, leading to more precise estimates of these counties. In some cases the estimates are similar to local community studies. For others, such as when our numbers are compared to those reported in the S.F.-based federation study, the estimates are substantially different.
It is also conceivable that the two Bay Area studies under- or over-estimate the size of the Jewish population. This type of bias is one of the inherent limitations of single, cross-sectional surveys. The goal of our project is not to replicate existing Jewish community studies; rather, it is to use the best available data and methods to produce reliable population estimates that are independent from the community surveys and can be used to gauge potential sources of bias and error in new community surveys that are done.
The fact is, with all of this haggling over the numbers, we have missed the real headline. The SSRI approach demonstrates that it is possible to develop an external, censuslike data source of the size and basic demographic composition of American Jews. It’s important to “get it right,” and on many levels we are there. The convergence of our national estimates with the recently published 2013 Pew study on American Jewry should put to rest the heated dispute about the overall size of the Jewish population and more specifically those Jews who identify as Jewish by religion (both estimate this group at 1.8 percent of the total U.S. population, or 4.2 million people).
The report and the website are part of SSRI’s ongoing effort to provide national and local estimates of the size and composition of the American Jewish population. We continue to incorporate more data and improve estimates, especially at the local level. Currently, local Jewish communities spend considerable resources to estimate the size of their Jewish populations.
Going forward, the only thing the Bay Area and other local Jewish communities will see disappear as a result of the SSRI approach is the hefty price tag associated with such studies.
Daniel Parmer is a research associate at the Steinhardt Social Research Institute at Brandeis University. He is co-author of “American Jewish Population Estimates: 2012.”